Why does this task definition throw an error?

Old Forum
1 
JavaExec x = task(type: JavaExec, name: "someTask")

Error:(38, 0) Cannot cast object ‘task ‘:{type=class org.gradle.api.tasks.JavaExec, name=android.Android}’’ with class ‘org.gradle.api.DefaultTask_Decorated’ to class ‘org.gradle.api.tasks.JavaExec’

Shouldn’t the cast work since a task of type JavaExec is created?

2

Not exactly sure what’s happening here, but it’s not a valid task declaration (task name needs to be a positional argument). Try:

JavaExec x = task("someTask", type: JavaExec)
3

Gradle is light-years better then most build tools.

Still I despise compiler magic when it comes to creating tasks. You can avoid it completely by using:

JavaExec x = tasks.create(name: "someTask", type: JavaExec)

Any build tool that goes beyond the very basics needs to be understood or easily analyzed by the user. This includes every line in the script. Sadly Groovy already offers - not one - but many ways to do the very same thing and Gradle introduces even more syntax sugar in order to type a few less characters. This is all confusing to beginners.

Maybe the Gradle team removes all the bad decisions for the 3.0+ release :wink:

4

‘task(“someTask”, type: JavaExec)’ is the regular ‘Project#task’ API for creating tasks, but the OP omitted a mandatory argument, and it’s possible that the compiler magic got in the way. Task declaration is the only case where Gradle uses compiler magic to enable special syntax (‘task someTask(type: JavaExec)’), and perhaps it will get deprecated at some point.

5

Actually I had to dig down to find the culprit DefinitionScriptTransformer in order to fully understand it :frowning:

In my opinion there should be ONE way to do this:

task.create(name: "someTask", type: JavaExec) {}

Adding a task to the collection of tasks should be explicit.

I know it would increase the size of build files a little but also make them much nicer to read. In the end it’s probably a question of taste and Gradle to a big extend is Groovy which has a very different philosophy then let’s say Python: http://legacy.python.org/dev/peps/pep-0020 :wink: